Rollup of 6 pull requests by JonathanBrouwer · Pull Request #162687 · rust-lang/rust

JonathanBrouwer · 2026-09-12T14:44:10Z

Successful merges:

Use GrowableBitSet in the main loop of rustc_mir_transform::sroa #162623 (Use GrowableBitSet in the main loop of rustc_mir_transform::sroa)
Disconnect rustc_codegen_ssa from rustc_mir_transform #162678 (Disconnect rustc_codegen_ssa from rustc_mir_transform)
Remove unused arguments of functions #162641 (Remove unused arguments of functions)
Rustdoc issue template: fix typo in comment ("thorugh") #162663 (Rustdoc issue template: fix typo in comment ("thorugh"))
Add E0747 explanation for type/const mismatch case #162684 (Add E0747 explanation for type/const mismatch case)
Stabilize Vec::from_fn #162685 (Stabilize Vec::from_fn)

After the separation from `DenseBitSet` and the removal of unused methods, growable bitsets have no need to track an explicit domain size separate from the length of their storage vec.

The bitset entries tracked by this code don't have a naturally fixed domain, so using GrowableBitSet makes more sense than repeatedly resizing a DenseBitSet.

The direct dependency from `rustc_codegen_ssa` to `rustc_mir_transform` allowed codegen to reuse some MIR-transform code for identifying unnecessary landing pads. However, we can achieve the same result by calling through a hook on `TyCtxt`, eliminating the crate dependency.

@panstromek

Use GrowableBitSet in the main loop of `rustc_mir_transform::sroa` - Follow-up to rust-lang#161957 --- The first commit is a cleanup based on rust-lang#161957 (comment) by @panstromek. After having disconnected GrowableBitSet from DenseBitSet and removed unused methods, there is no longer any reason to keep track of a separate `domain_size` in GrowableBitSet. After that, I wanted to get rid of `DenseBitSet::enlarge`, since having it around is not a good fit for the intended purpose of DenseBitSet as a fixed-domain set. After looking more closely at the code in `rustc_mir_transform::sroa` that uses it, I concluded that that code would be better off using GrowableBitSet instead. GrowableBitSet is just as dense, but avoids the need to set a fixed domain size in advance. The changes to SROA require adding `GrowableBitSet::union`, which is easier after having removed `domain_size`. (I am not deeply familiar with the SROA pass, but its usage of bitsets seems fairly straightforward in this case.) There should be no change to compiler output.

…uppe Disconnect `rustc_codegen_ssa` from `rustc_mir_transform` The direct dependency from `rustc_codegen_ssa` to `rustc_mir_transform` allowed codegen to reuse some MIR-transform code for identifying unnecessary landing pads (for rust-lang#143208). However, we can achieve the same result by calling through a hook on `TyCtxt`, eliminating the crate dependency. --- There should be no change to compiler output.

…yUwU Remove unused arguments of functions That these arguments are unused was hidden by the `#[trace::instrument]` macro, which uses the arguments. I don't see an easy way to avoid this from happening in the future.

…ypo, r=jieyouxu Rustdoc issue template: fix typo in comment ("thorugh")

@GuillaumeGomez

…umeGomez Add `E0747` explanation for `type/const` mismatch case Fixes rust-lang#162320 r? @GuillaumeGomez

…nna-kruppe Stabilize `Vec::from_fn` Tracking issue: rust-lang#149698.

JonathanBrouwer · 2026-09-12T14:44:19Z

@bors r+ p=5

Trying commonly failed jobs
@bors try jobs=dist-various-1,test-various,test-x86_64-gnu-aux,test-x86_64-gnu-llvm-21-3,test-x86_64-msvc-1,test-aarch64-apple-1,test-aarch64-apple-2,test-x86_64-mingw-1,test-i686-msvc,test-armhf-gnu

rust-bors · 2026-09-12T14:44:22Z

📌 Commit f91d429 has been approved by JonathanBrouwer

It is now in the queue for this repository.

Rollup of 6 pull requests try-job: dist-various-1 try-job: test-various try-job: test-x86_64-gnu-aux try-job: test-x86_64-gnu-llvm-21-3 try-job: test-x86_64-msvc-1 try-job: test-aarch64-apple-1 try-job: test-aarch64-apple-2 try-job: test-x86_64-mingw-1 try-job: test-i686-msvc try-job: test-armhf-gnu

…uwer Rollup of 6 pull requests Successful merges: - #162623 (Use GrowableBitSet in the main loop of `rustc_mir_transform::sroa`) - #162678 (Disconnect `rustc_codegen_ssa` from `rustc_mir_transform`) - #162641 (Remove unused arguments of functions) - #162663 (Rustdoc issue template: fix typo in comment ("thorugh")) - #162684 (Add `E0747` explanation for `type/const` mismatch case) - #162685 (Stabilize `Vec::from_fn`)

JonathanBrouwer · 2026-09-12T14:45:21Z

@bors yield

rust-bors · 2026-09-12T14:45:40Z

Auto build was cancelled. Cancelled workflows:

https://github.com/rust-lang/rust/actions/runs/34700165039

The next pull request likely to be tested is #160377.

rust-bors · 2026-09-12T17:46:00Z

☀️ Try build successful (CI)
Build commit: a1f535e (a1f535e3a625fd0856c63cfe81f3ad47bbab524b)
Base parent: 9c99d05 (9c99d05505bccb67912d68e05fe7fc7c58afcb41)

rust-bors · 2026-09-12T21:04:40Z

☀️ Test successful - CI
Approved by: JonathanBrouwer
Duration: 3h 13m 46s
Pushing 809936e to main...

github-actions · 2026-09-12T21:07:27Z

What is this?

This is an experimental post-merge analysis report that shows differences in test outcomes between the merged PR and its parent PR.

Comparing adcc5f3 (parent) -> 809936e (this PR)

Test differences

Show 393 test diffs

Stage 0

bit_set::tests::growable_union: [missing] -> pass (J0)

Stage 1

bit_set::tests::growable_union: [missing] -> pass (J1)

Additionally, 391 doctest diffs were found. These are ignored, as they are noisy.

Job group index

Test dashboard

Run

cargo run --manifest-path src/ci/citool/Cargo.toml -- \
    test-dashboard 809936eac66c547a5127ce1da805f0d3a6789b98 --output-dir test-dashboard

And then open test-dashboard/index.html in your browser to see an overview of all executed tests.

Job duration changes

test-x86_64-gnu-stdlib-semver-check: 11m 12s -> 18m 26s (+64.6%)
test-x86_64-gnu-gcc-core-tests: 11m 9s -> 18m 10s (+62.9%)
test-x86_64-mingw-2: 1h 53m -> 2h 50m (+50.1%)
test-x86_64-gnu-gcc: 58m 51s -> 1h 26m (+46.2%)
test-x86_64-gnu-debug: 1h 32m -> 2h 11m (+42.1%)
dist-powerpc64le-linux-musl: 1h 12m -> 1h 40m (+38.9%)
test-i686-gnu-1: 1h 40m -> 2h 18m (+38.4%)
test-x86_64-gnu-llvm-22-3: 1h 26m -> 1h 55m (+33.4%)
test-x86_64-gnu-llvm-21-2: 1h 44m -> 1h 11m (-32.0%)
dist-x86_64-msvc: 2h 27m -> 3h 12m (+30.8%)

How to interpret the job duration changes?

Job durations can vary a lot, based on the actual runner instance
that executed the job, system noise, invalidated caches, etc. The table above is provided
mostly for t-infra members, for simpler debugging of potential CI slow-downs.

rust-timer · 2026-09-12T22:03:26Z

Finished benchmarking commit (809936e): comparison URL.

Overall result: ✅ improvements - no action needed

@rustbot label: -perf-regression

Instruction count

Our most reliable metric. Used to determine the overall result above. However, even this metric can be noisy.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.4%	[-0.4%, -0.4%]	1
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results (primary -0.2%, secondary -2.5%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	0.5%	[0.4%, 0.5%]	3
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-2.0%	[-2.0%, -2.0%]	1
Improvements ✅ (secondary)	-2.5%	[-2.5%, -2.5%]	1
All ❌✅ (primary)	-0.2%	[-2.0%, 0.5%]	4

Cycles

Results (primary -0.5%, secondary -3.3%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	0.8%	[0.5%, 1.0%]	2
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-1.0%	[-2.2%, -0.6%]	5
Improvements ✅ (secondary)	-3.3%	[-4.0%, -2.6%]	2
All ❌✅ (primary)	-0.5%	[-2.2%, 1.0%]	7

Binary size

This perf run didn't have relevant results for this metric.

Bootstrap: 493.58s -> 493.911s (0.07%)
Artifact size: 406.93 MiB -> 406.90 MiB (-0.01%)

rust-bors · 2026-09-12T22:07:00Z

📌 Perf builds for each rolled up PR:

PR#	Message	Perf Build Sha
#162623	Use GrowableBitSet in the main loop of `rustc_mir_transform…	`06f13a980aea514196527b1aec662a0dabfb6531` (link)
#162678	Disconnect `rustc_codegen_ssa` from `rustc_mir_transform`	`03f495bb50da1f6802794c2207b48d9107db99e7` (link)
#162641	Remove unused arguments of functions	`0d7efb9b7c06d4474ea972d0654036e1906e8b08` (link)
#162663	Rustdoc issue template: fix typo in comment ("thorugh")	`eece2bb8088f52c105aafc5a765d30613646bd7a` (link)
#162684	Add `E0747` explanation for `type/const` mismatch case	`86e0d5bfec2c043c7cf96c980200639b1b78f4a6` (link)
#162685	Stabilize `Vec::from_fn`	`329ca725d0bd5bcc442dafa7bbed56a01ef455e0` (link)

parent commit: adcc5f3bdc

In the case of a perf regression, run the following command for each PR you suspect might be the cause: @rust-timer build $SHA

DanielEScherzer and others added 21 commits September 11, 2026 12:13

Rustdoc issue template: fix typo in comment ("thorugh")

a3be40f

Remove unused argument of write_splatted_call

fcec25c

Remove unused argument of simplify_rvalue

0957d02

Remove unused argument of check_let

86f0a13

Remove unused argument of process_registered_region_obligations

bb89d6f

Remove unused argument of lower_fn_decl

e1a4c77

Remove unused argument of try_match_macro_derive

338b24b

Remove unused argument of try_match_macro_attr

c690933

Remove unused argument of try_match_macro

de8eec9

Remove unused argument of unify_query_var_values

80e7183

docs(error_codes): document type/const mismatch case for E0747

8764372

Remove domain_size from GrowableBitSet

0a612a2

After the separation from `DenseBitSet` and the removal of unused methods, growable bitsets have no need to track an explicit domain size separate from the length of their storage vec.

Use GrowableBitSet in the main loop of rustc_mir_transform::sroa

16cd825

The bitset entries tracked by this code don't have a naturally fixed domain, so using GrowableBitSet makes more sense than repeatedly resizing a DenseBitSet.

Stabilize Vec::from_fn

d774bfa

Rollup merge of rust-lang#162663 - DanielEScherzer:rustdoc-template-t…

2725a26

…ypo, r=jieyouxu Rustdoc issue template: fix typo in comment ("thorugh")

Rollup merge of rust-lang#162684 - raushan728:issues/162320, r=Guilla…

d6570b4

…umeGomez Add `E0747` explanation for `type/const` mismatch case Fixes rust-lang#162320 r? @GuillaumeGomez

Rollup merge of rust-lang#162685 - EFanZh:stabilize-vec-from-fn, r=ha…

f91d429

…nna-kruppe Stabilize `Vec::from_fn` Tracking issue: rust-lang#149698.

rust-bors Bot added the rollup A PR which is a rollup label Sep 12, 2026

rust-bors Bot added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Sep 12, 2026

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rust-bors Bot added merged-by-bors This PR was explicitly merged by bors. and removed S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. labels Sep 12, 2026

rust-bors Bot merged commit 809936e into rust-lang:main Sep 12, 2026
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rustbot added this to the 1.100.0 milestone Sep 12, 2026

This was referenced Sep 12, 2026

move bug and span_bug macros to rustc_span #161873

Open

[POC] create an MVP for using Destruct for custom dtors #156090

Draft

[perf] Use a flat token stream representation when lexing #159378

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Rollup of 6 pull requests - #162687

Rollup of 6 pull requests#162687
rust-bors[bot] merged 21 commits into
rust-lang:mainfrom
JonathanBrouwer:rollup-nWh5YpQ

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Test differences

Stage 0

Stage 1

Job duration changes

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rust-timer commented Sep 12, 2026

Overall result: ✅ improvements - no action needed

Instruction count

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